1. Field of the Invention
The invention relates to a piezoelectric pressure transducer, with at least one piezoelectric measuring element arranged on a housing base part, which measuring element is connected on the side opposite the base part to a diaphragm sealing the base part and exposed to the pressure to be measured, and which bears against an electrode sheet during contact of one of its poles.
2. The Prior Art
Piezoelectric pressure transducers with diaphragms have been known for a long time in a variety of embodiments—see by way of example FIG. 3 in EP 352 773 or FIG. 1 in EP 90 871 A1. The pressure acting on the diaphragm from outside is transmitted as a force to the measuring element, which provides a charge, proportional to the pressure, to both poles in a manner that can be tapped and used further. Although the design of pressure transducers of this type is basically very simple, the contacting of the two poles and the positioning of the measuring elements in particular require a relatively high expenditure in terms of construction and production engineering, which has hitherto prevented a mass production at low cost desirable for many applications.
Furthermore, corresponding pressure transducers are known, for example, from AT 503 816 A in which a facilitation or improvement of the positioning of the measuring elements in the assembly of the transducer is rendered possible in that the measuring element or the measuring element stack is fixed to a lead electrode or to an electrode sheet making contact with one of its poles. However, the exact positioning with respect to the housing is thereby also carried out by means of additional elements, which furthermore entails additional expenditure in terms of construction and production engineering.
The object of the present invention is to improve a piezoelectric pressure transducer of the type mentioned at the outset such that the simple basic principle can be implemented consistently in a simple and cost-effective yet nevertheless high-quality mass production.